lxx 
found the opening in the trachea, but the soft parts were too 
much injured by decomposition to admit of an accurate exa- 
mination of the sac itself. The specimen from which the 
following account is taken is an adult, or probably, an old 
female. 
The cervical air-bag (fig. 1) occupies a broad and deeP 
depression on the forepart of the neck, immediately above 
the sternum and furculum bone, which latter in this bird is 
small and imperfect. The sac is not observable either in the 
living or the dead bird, unless distended, when it slowly bulges 
forwards and laterally, and fillsthe depression above-mentioned ; 
it is not, however, even then so prominent as to cause any 
remarkable deformity. On examining this region during life, 
the sac being undistended, I found the skin very moveable; it 
gave to the hand the sensation of great warmth, when con- 
trasted with the surrounding parts. The entire of the trachea 
was very moveable to either side ; but on fixing it steadily, and 
carrying the fingers along its forepart down to the sternum, 
the tube was felt a little above the latter to be flattened or 
depressed, but no slit or opening could be distinguished ; the 
sac was perfectly flaccid and compressed, and the communica- 
tion with the trachea was closed. This examination did not 
appear to cause any peculiar uneasiness in the part, or to 
excite any general irritation in the respiratory system. This 
bird, however, is very restless and timid, and very impatient 
under any restraint; it is also possessed of great muscular 
power, three or four men being required to secure it, and the 
attempt to do so is by no means free from danger, either to 
itself or to those around, as it struggles with great violence, 
and strikes with its powerful claws in every direction. I suc- 
ceeded twice, however, to my satisfaction, in feeling this 
region; and I think I am warranted in concluding that the 
tracheal opening is usually closed, and that it may be opened 
at the pleasure of the animal. - The plumage in this situation 
is thin and scanty; the feathers are chiefly of the double spe- 
